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EXHIBIT 21

SUBSIDIARIES OF
POTASH CORPORATION OF SASKATCHEWAN INC.

|                                                     |  |                              
|---------------------------------------------------- |  | -----------------------------
|                                                     |  | JURISDICTION OF INCORPORATION
|NAME OF ENTITY                                       |  | OR FORMATION                 
|                                                     |  |                              
|Potash Corporation of Saskatchewan Transport Limited |  | Saskatchewan                 
|Canpotex Bulk Terminals Ltd.                         |  | Canada                       
|PCS Sales (Canada) Inc.                              |  | Saskatchewan                 
|Potash Corporation of Saskatchewan (Florida) Inc.    |  | Florida                      
|PCS Sales (Iowa), Inc.                               |  | Iowa                         
|PCS Joint Venture, LP                                |  | Florida                      
|PCS Sales (Indiana), Inc.                            |  | Indiana                      
|609430 Saskatchewan Ltd.                             |  | Saskatchewan                 
|Potash Holding Company, Inc.                         |  | Delaware                     
|PCS Sales (USA), Inc.                                |  | Delaware                     
|PCS Administration (USA), Inc.                       |  | Delaware                     
|Phosphate Holding Company, Inc.                      |  | Delaware                     
|White Springs Agricultural Chemicals, Inc.           |  | Delaware                     
|PCS Phosphate Company, Inc.                          |  | Delaware                     
|Texasgulf Aircraft Inc.                              |  | Delaware                     
|Tg Corporation                                       |  | Delaware                     
|PCS Industrial Products Inc.                         |  | Delaware                     
|PCS Purified Phosphates                              |  | Virginia                     
|PCS Nitrogen, Inc.                                   |  | Delaware                     
|PCS USA LLC                                          |  | Delaware                     
|PCS Nitrogen Payroll Corporation                     |  | Delaware                     
|PCS Nitrogen Amm Term Corp II                        |  | Delaware                     
|PCS Nitrogen Amm Term Corp I                         |  | Texas                        
|Houston Ammonia Terminal, L.P.                       |  | Delaware                     
|AA Sulfuric Corp.                                    |  | Louisiana                    
|PCS Nitrogen Trinidad Fertilizer Corporation         |  | Delaware                     
|PCS Nitrogen Holding Company                         |  | Delaware                     
|PCS Nitrogen Limited                                 |  | Trinidad                     
|Augusta Service Company Inc.                         |  | Delaware                     
|PCS L.P. Inc.                                        |  | Delaware                     
|PCS Nitrogen Fertilizer Operations, Inc.             |  | Delaware                     
|PCS Nitrogen Ohio, L.P.                              |  | Delaware                     
|PCS Nitrogen Fertilizer, L.P.                        |  | Delaware                     
|PCS Nitrogen LCD Corporation                         |  | Delaware                     
|AC Industries                                        |  | Delaware                     
|PCS Nitrogen Trinidad Corporation                    |  | Delaware                     
|PCS Nitrogen Cayman Limited                          |  | Cayman                       
|PCS Nitrogen Trinidad Limited                        |  | Trinidad                     
|PCS Cassidy Lake Company                             |  | Ontario                      
|Chilkap Resources Ltd                                |  | Yukon                        
|628550 Saskatchewan Ltd.                             |  | Saskatchewan                 
|PCS (Barbados) Shipping Ltd.                         |  | Barbados                     
|Minera Saskatchewan Limitada                         |  | Chile                        
|Inversiones PCS Chile Limitada                       |  | Chile                        
|PCS Yumbes S.C.M.                                    |  | Chile                        
|PCS Fosfatos do Brasil Ltda.                         |  | Brazil                       
|PCS Chile I LLC                                      |  | Delaware                     
|PCS Chile II LLC                                     |  | Delaware                     
|El Roble Limitada                                    |  | Chile                        
|El Boldo Limitada                                    |  | Chile                        
|Sociedad Quimica y Minera de Chile S.A.              |  | Chile                        
|Israel Chemicals Ltd.                                |  | Israel                       
|PCS Hungary Holding Limited                          |  | Hungary